Plasma F2-isoprostane class VI isomers at 12-18 weeks of pregnancy are associated with later occurrence of preeclampsia

Association between F2-isoprostanes and self-reported stressors in pregnant americans of African and European ancestry

Background

Poor birth outcomes such as preterm birth/delivery disproportionately affect African Americans compared to White individuals. Reasons for this disparity are likely multifactorial, and include prenatal psychosocial stressors, and attendant increased lipid peroxidation; however, empirical data linking psychosocial stressors during pregnancy to oxidative status are limited.

Methods

We used established scales to measure five psychosocial stressors. Maternal adverse childhood experiences, financial stress, social support, anxiety, and depression were measured among 50 African American and White pregnant women enrolled in the Stress and Health in Pregnancy cohort. Liquid chromatography-tandem mass spectrometry was used to measure biomarkers of oxidative stress (four urinary F2-isoprostane isomers), to estimate oxidative status. Linear regression models were used to evaluate associations between psychosocial stressors, prenatal oxidative status and preterm birth.

Results

After adjusting for maternal obesity, gestational diabetes, and cigarette smoking, African American women with higher oxidative status were more likely to report higher maternal adverse childhood experience scores (β = 0.16, se = 1.07, p-value = 0.024) and depression scores (β = 0.05, se = 0.02, p = 0.014). Higher oxidative status was also associated with lower gestational age at birth (β = -0.13, se = 0.06, p = 0.04) in this population. These associations were not apparent in Whites. However, none of the cross-product terms for race/ethnicity and social stressors reached statistical significance (p > 0.05).

Conclusion

While the small sample size limits inference, our novel data suggest that psychosocial stressors may contribute significantly to oxidative stress during pregnancy, and preterm birth or delivery African Americans. If replicated in larger studies, these findings would support oxidative stress reduction using established dietary or pharmacological approaches present a potential avenue to mitigate adverse effects of psychosocial stressors on birth outcomes.

Impact of Climate Change on Dietary Nutritional Quality and Implications for Asthma and Allergy

Asthma and allergic disorders are common in childhood with genetic and environmental determinants of disease that include prenatal nutritional exposures such as long-chain polyunsaturated fatty acids and antioxidants. Global climate change is implicated in asthma and allergic disorder morbidity with potential mechanisms including perturbations of ecosystems. There is support that environmental and climatic changes such as increasing global temperate and carbon dioxide levels affect aquatic and agricultural ecosystems with subsequent alterations in long-chain polyunsaturated fatty acid availability and nutrient quality and antioxidant capacity of certain crops, respectively. This article discusses asthma epidemiology and the influence of global climate change.

Prostaglandin Metabolome Profiles in Zebrafish (Danio rerio) Exposed to Acetochlor and Butachlor

Prostaglandins (PGs) are critically important signaling molecules that play key roles in normal and pathophysiological processes. Many endocrine-disrupting chemicals have been found to suppress PG synthesis; however, studies about the effects of pesticides on PGs are limited. The effects of two known endocrine disrupting herbicides, acetochlor (AC) and butachlor (BC), on PG metabolites in zebrafish (Danio rerio) females and males were studied using widely targeted metabolomics analysis based on ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In total, 40 PG metabolites were detected in 24 zebrafish samples, including female and male samples, with and without exposure to AC or BC at the sub-lethal concentration of 100 μg/L for 96 h. Among them, 19 PGs significantly responded to AC or BC treatment, including 18 PGs that were upregulated. The enzyme-linked immunosorbent assay (ELISA) test in zebrafish showed BC could cause significant upregulation of an isoprostane metabolite, 5-iPF2a-VI, which is positively related to the elevated level of reactive oxygen species (ROS). The present study guides us to conduct a further study to determine whether PG metabolites, including isoprostanes, could be potential biomarkers for chloracetamide herbicides.

Inflammation and oxidative stress as mediators of the impacts of environmental exposures on human pregnancy: Evidence from oxylipins

Inflammation and oxidative stress play major roles in healthy and pathological pregnancy. Environmental exposure to chemical pollutants may adversely affect maternal and fetal health in pregnancy by dysregulating these critical underlying processes of inflammation and oxidative stress. Oxylipins are bioactive lipids that play a major role in regulating inflammation and increasing lines of evidence point towards an importance in pregnancy. The biosynthetic production of oxylipins requires oxygenation of polyunsaturated fatty acids, which can occur through several well-characterized enzymatic and nonenzymatic pathways. This review describes the state of the science of epidemiologic evidence on oxylipin production in pregnancy and its association with 1) key pregnancy outcomes and 2) environmental exposures. We searched PubMed for studies of pregnancy that measured one or more oxylipin analytes during pregnancy or delivery. We evaluated oxylipin associations with three categories of adverse pregnancy outcomes, including preeclampsia, preterm birth, and fetal growth restriction, along with several categories of environmental pollutants. The majority of studies evaluated one to two oxylipins, most of which focused on oxylipins produced from nonenzymatic processes of oxidative stress. However, an increasing number of recent studies have leveraged technological advancements to profile a large number of oxylipins produced from distinct biosynthetic pathways. Although the literature indicated robust evidence that oxylipins produced via nonenzymatic pathways are associated with pregnancy outcomes and environmental exposures, evidence for enzymatically produced oxylipins showed that associations may differ between biosynthetic pathways. Along with summarizing this evidence, we review promising therapeutic options to regulate oxylipin production and provide a set of recommendations for future epidemiologic studies in these research areas. Further evidence is needed to improve our understanding of how oxylipins may act as key biological mediators for the adverse effects of environmental pollutants on pregnancy outcomes.

Prediction of pregnancy-related hypertensive disorders using metabolomics: a systematic review

OBJECTIVE

To determine the accuracy of metabolomics in predicting hypertensive disorders in pregnancy.

DESIGN

Systematic review of observational studies.

DATA SOURCES AND STUDY ELIGIBILITY CRITERIA

An electronic literature search was performed in June 2019 and February 2022. Two researchers independently selected studies published between 1998 and 2022 on metabolomic techniques applied to predict the condition; subsequently, they extracted data and performed quality assessment. Discrepancies were dealt with a third reviewer. The primary outcome was pre-eclampsia. Cohort or case-control studies were eligible when maternal samples were taken before diagnosis of the hypertensive disorder.

STUDY APPRAISAL AND SYNTHESIS METHODS

Data on study design, maternal characteristics, how hypertension was diagnosed, metabolomics details and metabolites, and accuracy were independently extracted by two authors.

RESULTS

Among 4613 initially identified studies on metabolomics, 68 were read in full text and 32 articles were included. Studies were excluded due to duplicated data, study design or lack of identification of metabolites. Metabolomics was applied mainly in the second trimester; the most common technique was liquid-chromatography coupled to mass spectrometry. Among the 122 different metabolites found, there were 23 amino acids and 21 fatty acids. Most of the metabolites were involved with ammonia recycling; amino acid metabolism; arachidonic acid metabolism; lipid transport, metabolism and peroxidation; fatty acid metabolism; cell signalling; galactose metabolism; nucleotide sugars metabolism; lactose degradation; and glycerolipid metabolism. Only citrate was a common metabolite for prediction of early-onset and late-onset pre-eclampsia. Vitamin D was the only metabolite in common for pre-eclampsia and gestational hypertension prediction. Meta-analysis was not performed due to lack of appropriate standardised data.

CONCLUSIONS AND IMPLICATIONS

Metabolite signatures may contribute to further insights into the pathogenesis of pre-eclampsia and support screening tests. Nevertheless, it is mandatory to validate such methods in larger studies with a heterogeneous population to ascertain the potential for their use in clinical practice.

PROSPERO REGISTRATION NUMBER

CRD42018097409.

Impact of Dairy Intake on Plasma F2-IsoProstane Profiles in Overweight Subjects with Hyperinsulinemia: A Randomized Crossover Trial

F₂-IsoProstanes (F₂-IsoPs) are major biomarkers of oxidative stress and are associated with type 2 diabetes (T2D). Further, plasma levels of F₂-IsoPs may be modified by dairy products. The aim is to investigate the effect of high dairy product (HD) consumption compared to an adequate dairy product (AD) consumption on the level of F₂-IsoPs among hyperinsulinemic subjects. In this crossover study, participants were randomized in two groups: HD (≥4 servings/day), or AD (≤2 servings/day) for six weeks. Fasting blood glucose and insulin were measured. The homeostatic model assessment of insulin resistance (HOMA-IR) was calculated. Six isomers of F₂-IsoPs were quantified by HPLC-MS/MS. Twenty-seven subjects with hyperinsulinemia (mean age; 55 ± 13 years, BMI; 31.4 ± 3.3 kg/m2) were included. Fasting glucose, insulin and HOMA-IR were unchanged after HD or AD intervention. After HD intake, the total level of F₂-IsoPs (p = 0.03), 5-F_2t-IsoP (p = 0.002), and 8-F_2t-IsoP (p = 0.004) decreased compared to AD. The 15-F_2t-IsoP tended to be positively correlated with fasting blood glucose (r = 0.39, p = 0.08). Generally, F₂-IsoPs levels were higher among men compared to women regardless of the dairy intake. Overall, intake of HD decreased plasma levels of F₂-IsoPs compared to AD without modifying glycemic parameters.

The plasma antioxidant vitamin status of the INTAPP cohort examined: The unsuspected importance of β-carotene and γ-tocopherol in preeclampsia

OBJECTIVE

Examine the levels of plasma antioxidant vitamins before and during a treatment with placebo or vitamin E + C supplement to prevent preeclampsia (PE).

STUDY DESIGN

Per-protocol analysis of a subset group of pregnant women (n = 295) from the International Trial of Antioxidants for the Prevention of PE (INTAPP) randomized case-control study. Normotensive receiving placebo or vitamins (n = 115 and 87 respectively) were compared to gestational hypertension (GH) without proteinuria (n = 30 and 27) and PE (n = 21 and 15). Vitamin quantification was performed at 12-18, 24-26 and 32-34 weeks of gestation.

MAIN OUTCOME MEASURES

Coenzyme (Co) Q₁₀, β-carotene and vitamins E (α and γ forms) plasma levels.

RESULTS

Vitamin E + C supplementation was found to increase the α-tocopherol levels by 40% but was associated with a 57% decrease in the γ-tocopherol isoform for all study groups (p < 0.001). The β -carotene was lower in the PE than in the normotensive and GH groups (p < 0.001) while the level of CoQ₁₀ remained unaffected.

CONCLUSIONS

A more personalized approach that target the suboptimal levels of specific antioxidants without disturbing the α/γ-tocopherol ratio could be a more successful approach to counteract oxidative stress in PE.

Hydroxychloroquine prophylaxis for preeclampsia, hypertension and prematurity in pregnant patients with systemic lupus erythematosus: A meta-analysis

OBJECTIVES

This meta-analysis aimed to evaluate the effectiveness of HCQ in improving the maternal and fetal outcomes in pregnancies with SLE.

METHODS

A literature search was conducted using PubMed, MEDLINE, EMBASE, and the Cochrane database for relevant English language articles, and Wanfang, CNKI and VIP for Chinese articles, from the databases' inception to April 30, 2020. These studies compared the maternal and/or fetal outcomes between pregnant patients with SLE who were administered HCQ during pregnancy (HCQ+ group) and those who were not administered HCQ (HCQ- group). Two investigators extracted the data and assessed the quality using the Newcastle-Ottawa Scale (NOS) and GRADE criteria independently. Odds ratio (OR) and 95% confidence intervals (CIs) were calculated. All statistical analyses were conducted using the Stata 12.0 software.

RESULTS

Nine studies involving 1132 pregnancies were included in the study (3 case controls, 2 prospective cohorts, 4 retrospective cohorts). Preeclampsia, gestational hypertension, and prematurity were significantly lower in the HCQ+ group than in the HCQ- group (OR 0.35, 95% CI 0.21-0.59), (OR 0.41, 95% CI 0.19-0.89) and (OR 0.55, 95% CI 0.36-0.86), respectively. There were no significant differences in the rates of HELLP Syndrome (OR 0.88, 95% CI 0.19-3.96), gestational diabetes (OR 2.3, 95% CI 0.44-12.12), thrombotic events (OR 0.26, 95% CI 0.05-1.51), spontaneous abortion (OR 1.77, 95% CI 0.96-3.26), premature rupture of membranes (OR 0.58, 95% CI 0.24-1.39), oligohydramnios (OR 0.90, 95% CI 0.38-2.14), live birth (OR 1.22, 95% CI 0.60-2.47), stillbirth (OR 1.00, 95% CI 0.50-2.00), congenital malformation (OR 0.53, 95% CI 0.14-2.04), low birth weight (OR 0.77, 95% CI 0.43-1.39), intrauterine distress (OR 1.07, 95% CI 0.41-2.76,), intrauterine growth restriction (OR 0.57, 95% CI 0.06-5.43), or five-minute APGAR score <7 (OR 0.72, 95% CI 0.20-2.58) between the two groups.

CONCLUSIONS

HCQ treatment during pregnancy could reduce the risk of preeclampsia, pregnancy hypertension and prematurity in SLE patients. The certainty of evidence is high but majority of the studies included are retrospective studies and not randomized controlled trials. Therefore, the multidisciplinary management of pregnant patients with SLE should promote HCQ use, irrespective of disease activity or severity.

Long chain omega-3 fatty acids and their oxidized metabolites are associated with reduced prostate tumor growth

INTRODUCTION

Cancer has been associated with increased oxidative stress and deregulation of bioactive oxylipins derived from long-chain polyunsaturated fatty acids (LC-PUFA) like arachidonic acid (AA). There is a debate whether ω-3 LC-PUFA could promote or prevent prostate tumor growth through immune modulation and reduction of oxidative stress. Our aim was to study the association between enzymatically or non-enzymatically produced oxidized-LC-PUFA metabolites and tumor growth in an immune-competent eugonadal and castrated C57BL/6 male mice injected with TRAMP-C2 prostate tumor cells, fed with ω-3 or ω-6 LC-PUFA-rich diets.

MATERIALS AND METHODS

Tumor fatty acids were profiled by gas chromatography and 26 metabolites derived from either AA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were assessed by liquid chromatography-mass spectrometry.

RESULTS

The enriched ω-3 diet did not reduce oxidative stress overall in tumors but favored the formation of ω-3 rather than ω-6 derived isoprostanoids. We discovered that EPA and its oxidized-derivatives like F₃-isoprostanes and prostaglandin (PG)F_3α, were inversely correlated with tumor volume (spearman correlations and T-test, p<0.05). In contrast, F₂-isoprostanes, adrenic acid, docosapentaenoic acid (DPA_ω-6) and PGE₂ were positively correlated with tumor volume. Interestingly, F₄-neuroprostanes, PGD₂, PGF_2α, and thromboxane were specifically increased in TRAMP-C2 tumors of castrated mice compared to those of eugonadal mice.

DISCUSSION

Decreasing tumor growth under ω-3 diet could be attributed in part to increased levels of EPA and its oxidized-derivatives, a reduced level of pro-angiogenic PGE₂ and increased levels of F₄-neuroprostanes and resolvins content in tumors, suspected of having anti-proliferative and anti-inflammatory effects.

Recent progress in the LC-MS/MS analysis of oxidative stress biomarkers

The presence of a dynamic and balanced equilibrium between the production of reactive oxygen (ROS) and nitrogen (RNS) species and the in-house antioxidant defense mechanisms is characteristic for a healthy body. During oxidative stress (OS), this balance is switched to increased production of ROS and RNS, exceeding the capacity of physiological antioxidant systems. This can cause damage to biological molecules, leading to loss of function and even cell death. Nowadays, there is increasing scientific and clinical interest in OS and the associated parameters to measure the degree of OS in biofluids. An increasing number of reports using LC-MS/MS methods for the analysis of OS biomarkers can be found. Since bioanalysis is usually complicated by matrix effects, various types of cleanup procedures are used to effectively separate the biomarkers from the matrix. This is an essential part of the analysis to prepare a reproducible and homogenous solution suitable for injection onto the column. The present review gives a summary of the chromatographic methods used for the determination of OS biomarkers in both urine and plasma, serum, and whole blood samples. The first part mainly describes the biological background of the different OS biomarkers, while the second part reports examples of chromatographic methods for the analysis of different metabolites connected with OS in biofluids, covering a period from 2015 till early 2020. The selected examples mainly include LC-MS/MS methods for isoprostanes, oxidized proteins, oxidized lipoproteins, and DNA/RNA biomarkers. The last part explains the clinical relevance of this review.

Maternal vitamin D, oxidative stress, and pre-eclampsia

OBJECTIVE

To examine the associations between risk of pre-eclampsia and pregnancy levels of maternal 25-hydroxyvitamin D (25[OH]D) and oxidative stress biomarkers.

METHODS

A nested case-control study (n = 99; 34 cases; 65 controls) within a prospective pregnancy cohort. Maternal 25(OH)D and oxidative stress markers (six isomers of F₂ -isoprostanes; F₂ -isoPs) were measured in plasma at 12-18 and 24-26 gestational weeks. Vitamin D deficiency was defined as 25[OH]D less than 50 nmol/L.

RESULTS

Maternal vitamin D deficiency was associated with increased 8-iso-PGF_2α (P = 0.037), 15(R)-PGF_2α (P = 0.004), (±)5-iPF_2α -VI (P = 0.026) at 12-18 weeks. Vitamin D deficiency was inversely associated with 8-iso-PGF_2α (P = 0.019) and (±)5-iPF_2α -VI isomer (P = 0.010) at 24-26 weeks. Both maternal vitamin D deficiency (adjusted odds ratio [aOR], 4.79; 95% confidence interval [CI], 1.67-13.75) and increased (±)5-iPF_2α -VI (aOR, 2.46; 95% CI, 1.16-5.22) at 24-26 weeks were associated with risk of pre-eclampsia. However, the interaction test between 25(OH)D and (±)5-iPF_2α -VI was not significant (P = 0.143).

CONCLUSION

Plasma 25(OH)D below 50 nmol/L was associated with increased oxidative stress levels during pregnancy as measured by two F₂ -isoP isomers, including the well-studied marker 8-iso-PGF_2α . Whether vitamin D-induced oxidative stress mediates the risk of pre-eclampsia warrants future study.

Omega-3 fatty acid supplement use and oxidative stress levels in pregnancy

Oxidative stress is a biological imbalance in reactive oxygen species and antioxidants. Increased oxidative stress during pregnancy has been associated with adverse birth outcomes. Omega-3 fatty acid (n-3 FA) supplementation may decrease oxidative stress; however, this relationship is seldom examined during pregnancy. This study assessed the association between n-3 FA supplement use during pregnancy and urinary oxidative stress biomarker concentrations. Data came from The Infant Development and the Environment Study (TIDES), a prospective cohort study that recruited pregnant women in 4 US cities between 2010-2012. Third trimester n-3 FA intake was self-reported. Third trimester urinary 8-iso-prostaglandin F2α (8-iso-PGF2α) was measured as an oxidative stress biomarker. Additionally, we measured the major metabolite of 8-iso-PGF2α and Prostaglandin F2α (PGF2α) and utilized the 8-iso-PGF2α to PGF2α ratio to calculate the change in 8-iso-PGF2α reflecting oxidative stress versus inflammation. Adjusted linear models were used to determine associations with control for confounding. Of 725 women, 165 reported n-3 FA supplement use in the third trimester. In adjusted linear models, n-3 FA use was associated with 10.2% lower levels of 8-iso-PGF2α (95% Confidence Interval [CI]: -19.6, 0.25) and 10.3% lower levels of the metabolite (95% CI: -17.1, -2.91). No associations were observed with PGF2α. The lower levels of 8-iso-PGF2α appeared to reflect a decrease in oxidative stress (percent change with supplement use: -18.7, 95% CI: -30.1, -5.32) rather than inflammation. Overall, third trimester n-3 FA intake was associated with lower concentrations of 8-iso-PGF2α and its metabolite, suggesting a decrease in maternal oxidative stress during pregnancy.

Hydroxychloroquine Mitigates the Production of 8-Isoprostane and Improves Vascular Dysfunction: Implications for Treating Preeclampsia

In preeclampsia, widespread maternal endothelial dysfunction is often secondary to excessive generation of placental-derived anti-angiogenic factors, including soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), along with proinflammatory cytokines such as tumour necrosis factor-α (TNF-α) and activin A, understanding of which offers potential opportunities for the development of novel therapies. The antimalarial hydroxychloroquine is an anti-inflammatory drug improving endothelial homeostasis in lupus. It has not been explored as to whether it can improve placental and endothelial function in preeclampsia. In this in vitro study, term placental explants were used to assess the effects of hydroxychloroquine on placental production of sFlt-1, sEng, TNF-α, activin A, and 8-isoprostane after exposure to hypoxic injury or oxidative stress. Similarly, human umbilical vein endothelial cells (HUVECs) were used to assess the effects of hydroxychloroquine on in vitro markers of endothelial dysfunction. Hydroxychloroquine had no effect on the release of sFlt-1, sEng, TNF-α, activin A, or 8-isoprostane from placental explants exposed to hypoxic injury or oxidative stress. However, hydroxychloroquine mitigated TNF-α-induced HUVEC production of 8-isoprostane and Nicotinanamide adenine dinucleotide phosphate (NADPH) oxidase expression. Hydroxychloroquine also mitigated TNF-α and preeclamptic serum-induced HUVEC monolayer permeability and rescued the loss of zona occludens protein zona occludens 1 (ZO-1). Although hydroxychloroquine had no apparent effects on trophoblast function, it may be a useful endothelial protectant in women presenting with preeclampsia.

Biomarkers of oxidative stress in the fetus and in the newborn

The dynamic field of perinatology entails ever-increasing search for molecular mechanisms of neonatal diseases, especially in the domain of fetal growth and neurodevelopmental outcome. There is an urgent need for new molecular biomarkers, to early identify newborn at high risk for developing diseases and to provide new treatment targets. The interest in biomarkers of oxidative stress in perinatal period have begun to grow in the last century, when it was evidenced the importance of the free radicals generation underlying the various disease conditions. To date, interesting researches have been carried out, representing milestones for implementation of oxidative stress biomarkers in perinatal medicine. Use of a panel of "oxidative stress biomarkers", particularly non protein bound iron, advanced oxidative protein products and isoprostanes, may provide valuable information regarding functional pathways underlying free radical mediated diseases of newborns and their early identification and prevention. Here, we will review recent advances and the current knowledge on the application of biomarkers of oxidative stress in neonatal/perinatal medicine including novel biomarker discovery, defining yet unrecognized biologic therapeutic targets, and linking of oxidative stress biomarkers to relevant standard indices and long-term outcomes.

Update on oxidative stress and inflammation in pregnant women, unborn children (nasciturus), and newborns - Nutritional and dietary effects

The scientific background of perinatal pathology, regarding both mother and offspring, from the lipidomic perspective, has highlighted the possibility of identifying new, promising clinical markers of oxidative stress and inflammation, closely related to the normal development of unborn and newborn children, together with their application. In this regard, in recent years, significant advances have been achieved, assisted by both newly developed analytical tools and basic knowledge on the biological implications of oxylipins. Hence, in the light of this recent progress, this review aims to provide an update on the relevance of human oxylipins during pregnancy and in the unborn and newborn child, covering two fundamental aspects. Firstly, the evidence from human clinical studies and dietary intervention trials will be used to shed light on the extent to which dietary supplementation can modulate the lipidomic markers of oxidative stress and inflammation in the perinatal state, emphasizing the role of the placenta and metabolic disturbances in the mother and fetus. The second part of this article comprises a review of existing data on specific pathophysiological aspects of human reproduction, in relation to lipidomic markers in pregnant women, unborn children, and newborn children. The information reviewed here evidences the current opportunity to correct reproductive disturbances, in the framework of lipidomics, by fine-tuning dietary interventions.

Physical fitness is associated with prostaglandin F2α isomers during pregnancy

INTRODUCTION

Pregnancy and physical activity are associated with oxidative stress and immune changes. We hypothesized that pregnant women physically more active in early pregnancy will display a better oxidative stress management and inflammatory response later in pregnancy compared with less active pregnant women.

MATERIAL AND METHODS

Maternal physical activity using accelerometry monitors for 1 week and cardiorespiratory fitness (VO₂ at anaerobic threshold) were assessed at 14-18 weeks in 58 pregnant women. Plasma and erythrocytes membrane samples were obtained from maternal blood samples at 14-18 and 34-37 weeks of pregnancy. Pro-inflammatory prostaglandin (PG) F_2α and oxidative stress-derived F₂-isoprostanes were measured by high-performance liquid chromatography coupled to tandem mass spectrometry.

RESULTS

Higher physical activity levels at 14-18 weeks measured by mean counts per minute, >30 min/d of moderate to vigorous activity or >6500 steps/d at 14-18 weeks of pregnancy were associated with lower levels of total plasmatic PGF_2α later in pregnancy. Concentrations of 5 F₂-isomers in erythrocyte membranes in late pregnancy were significantly higher in the third (17.5-19.5 mL kg^-1 min^-1) and/or fourth (19.6-27.7 mL kg^-1 min^-1) quartiles of cardio-respiratory fitness compared to the first quartile (13.9-15.9 mL kg^-1 min^-1).

CONCLUSIONS

Overall, higher cardio-respiratory fitness in early pregnancy is associated with enhanced erythrocyte membranes oxidation at 34-37 weeks reflecting a higher oxygen transfer capacity. Also, the most active women experienced lower circulating levels of pro-inflammatory PGF_2α in plasma at 34-37 weeks, a marker associated with adverse antenatal inflammation-associated conditions. These results support the practice of physical activity by pregnant women.

F2-isoprostanes and fatty acids profile in early pregnancy complicated by pre-existing diabetes

BACKGROUND

Diabetes and pregnancy are both associated with oxidative stress, characterized by an increase of F₂-isoprostanes from the non-enzymatic oxidation of arachidonic acid, a n - 6 polyunsaturated fatty acid (PUFA). We hypothesized that pregnant women with pre-existing diabetes will be characterized by elevated levels of specific F₂-isoPs isomers and altered PUFA composition in plasma early pregnancy when compared to normoglycemic controls.

METHODS

Plasma samples from 23 women with uncomplicated pregnancies and 11 women with pre-existing diabetes in pregnancy were collected between 12 and 18 weeks of pregnancy (MIROS cohort). Six F₂-isoprostanes isomers were measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Fatty acids concentrations in plasmatic phospholipids were measured by gas chromatography coupled to a flame ionization detector.

RESULTS

F₂-isoprostanes, specifically the 8-iso-15(R)-PGF₂α levels, were 67% higher in diabetic than normoglycemic pregnancies (p = 0.026). The total n - 6 PUFA and arachidonic acid level did not differ between study groups. In contrast, total n - 3 level was 32% lower in diabetic pregnancies than in controls (p = 0.002); EPA(20:5) and DHA(22:6) being specifically reduced (p = 0.035 and p = 0.003 respectively). Delta-6-desaturase (D6D) activity index, calculated using fatty acid ratios, was 9% lower in pre-existing diabetes than in controls (p = 0.042).

CONCLUSIONS

Pre-existing diabetes in early pregnancy displays a distinctive F₂-isoprostanes profile when compared to other pathologies of pregnancy, such as preeclampsia, as previously assessed in the same cohort.

Dietary fats and F2-isoprostanes: A review of the clinical evidence

Evidence supports that a high dietary fat intake increases oxidative stress and the risk of diet-induced metabolic disorders such as obesity, diabetes and cardiovascular diseases. F₂-isoprostanes (F₂-isoP) are formed by the non-enzymatic oxidation of arachidonic acid and are widely used as reliable biomarkers of oxidative stress in clinical studies. Dietary fats may influence F₂-isoP levels, as they (1) are metabolic substrates for their formation, (2) modify the lipid composition of tissues, and (3) affect the plasma lipoprotein concentrations which are involved in F₂-isoP transport. This review examined the latest clinical evidence on how dietary fats can affect blood circulation and excretion of F₂-isoP in individuals with healthy or deteriorated metabolic profiles. Clinical studies reported that saturated or monounsaturated fat-rich diets did not affect F₂-isoP levels in adults with healthy or deteriorated metabolic profiles. Though, ω-3 polyunsaturated fatty acids decreased F₂-isoP levels in numerous studies, whereas trans-fatty acids raised F₂-isoP excretion. Yet, the reported heterogeneous results reveal important considerations, such as the health status of the participants, the biological fluids used to determine F₂-isoP, the analytical methods employed and the specific F₂-isoP isomers detected. Therefore, future clinical studies should be designed in order to consider these issues in the studies of the effects of fat intake on oxidative stress.

Distinct differences in serum eicosanoids in healthy, enteritis and colorectal cancer individuals

BACKGROUND

Eicosanoids as inflammatory mediators take part in the regulation of disease progression. However, the application of serum eicosanoid in disease progression identification was still uncertain.

METHODS

Serum from 52 healthy volunteers, 34 enteritis patients and 55 colorectal cancer (CRC) patients were collected. Ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was used to analyze the change of serum eicosanoids.

RESULTS

Of 158 eicosanoids, we found that lower levels of anti-inflammatory eicosanoids 13-HOTrE, 9-HOTrE, DHA, 11-HETE and 12-HHT were observed in enteritis and CRC group compared with healthy group, meanwhile the content of 5-iPF2α-VI as oxidative stress mediator in enteritis and CRC group was greater than that in healthy groups. Moreover, 9-HODE, 13-HODE, 12,13-diHOME, 8-HETE and 15-HETE were dramatically decrease in CRC group compared with non-CRC group. Additionally, the change of 5-, 12- and 15-HETE content in serum sample was associated with progression from healthy to enteritis, finally to CRC. No significant difference between serum eicosanoids and the expression of CerbB-2 and Ki67 were observed.

CONCLUSION

Serum eicosanoids might be used as a possible biomarker for identifying among health, enteritis and CRC.

Modulation of the biomarkers of inflammation and oxidative stress by ruminant trans fatty acids and dairy proteins in vascular endothelial cells (HUVEC)

This study aimed to determine whether dairy macronutrients alter markers of inflammation and oxidative stress in endothelial cells. Human endothelial cells (HUVEC) were treated with ruminant trans fatty acids (rTFA), either trans-vaccenic acid (tVA) or trans-palmitoleic acid (tPA), whey protein hydrolysate, leucine or combinations of rTFA and dairy protein compounds. Industrial TFA elaidic acid (EA) was also investigated and compared with rTFA. Inflammatory prostaglandins (PG) and F₂-isoprostanes (F₂-isoP) isomers, markers of oxidative stress, were assessed in cell supernatants by LC-MS/MS. Both tVA and tPA, as well as whey protein hydrolysate, decreased TNFα-induced PG excretion. Combinations of rTFA and dairy protein compounds decreased inflammation to a similar extent than rTFA alone. EA increased class VI F₂-isoP isomers, whereas tVA mostly raised class III isomers. In summary, rTFA decreased inflammatory markers and increased oxidative stress markers in endothelial cells. Combinations of rTFA with whey proteins or leucine showed no additive effect.

Isoprostanes, neuroprostanes and phytoprostanes: An overview of 25years of research in chemistry and biology

Since the beginning of the 1990's diverse types of metabolites originating from polyunsaturated fatty acids, formed under autooxidative conditions were discovered. Known as prostaglandin isomers (or isoprostanoids) originating from arachidonic acid, neuroprostanes from docosahexaenoic acid, and phytoprostanes from α-linolenic acid proved to be prevalent in biology. The syntheses of these compounds by organic chemists and the development of sophisticated mass spectrometry methods has boosted our understanding of the isoprostanoid biology. In recent years, it has become accepted that these molecules not only serve as markers of oxidative damage but also exhibit a wide range of bioactivities. In addition, isoprostanoids have emerged as indicators of oxidative stress in humans and their environment. This review explores in detail the isoprostanoid chemistry and biology that has been achieved in the past three decades.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures.

In this meta-analysis, the F₂-isoprostane, 8-iso-PGF_2α, was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges’ g) in 8-iso-PGF_2α levels between affected and control populations were calculated.

The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF_2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF_2α levels (g<0.8) were found in the following conditions: hypertension (g=0.4), metabolic syndrome (g=0.5), asthma (g=0.4), and tobacco smoking (g=0.7). In contrast, large increases in 8-iso-PGF_2α levels were observed in pathologies of the kidney, e.g., chronic renal insufficiency (g=1.9), obstructive sleep apnoea (g=1.1), and pre-eclampsia (g=1.1), as well as respiratory tract disorders, e.g., cystic fibrosis (g=2.3).

In conclusion, we have established a quantitative classification for the level of 8-iso-PGF_2α generation in different human pathologies and exposures based on a comprehensive meta-analysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation.

•

Oxidative damage is highly variable in human conditions as measured by F₂-isoprostanes.

•

Respiratory tract and urogenital diseases have the highest F₂-isoprostanes.

•

Cancer and cardiovascular diseases have surprisingly low F₂-isoprostanes.

Going retro: Oxidative stress biomarkers in modern redox biology

The field of redox biology is inherently intertwined with oxidative stress biomarkers. Oxidative stress biomarkers have been utilized for many different objectives. Our analysis indicates that oxidative stress biomarkers have several salient applications: (1) diagnosing oxidative stress, (2) pinpointing likely redox components in a physiological or pathological process and (3) estimating the severity, progression and/or regression of a disease. On the contrary, oxidative stress biomarkers do not report on redox signaling. Alternative approaches to gain more mechanistic insights are: (1) measuring molecules that are integrated in pathways linking redox biochemistry with physiology, (2) using the exomarker approach and (3) exploiting -omics techniques. More sophisticated approaches and large trials are needed to establish oxidative stress biomarkers in the clinical setting.